\documentclass[preview]{standalone}

\usepackage{graphicx}
\usepackage{subfigure}
\usepackage{tikz}
\usetikzlibrary{decorations.pathmorphing}

\begin{document}
\begin{figure}
\centering
\subfigure{
\resizebox{\linewidth}{!}{%
\begin{tikzpicture}[<-,shorten >=1pt,auto,
  thick,main node/.style={circle,draw,font=\sffamily\Large\bfseries}]
  [scale=.40,auto=right,every node/.style={circle}]
  \node (n7) at (7,1) {7};
  \node (n6) at (5,1) {6};
  \node (n5) at (4,1)  {5};
  \node (n4) at (1,1)  {4};
  \node (n3) at (5,2) {3};
  \node (n2) at (3,2)  {2};
  \node (n1) at (4,3)  {1};
        
    \path[every node/.style={font=\sffamily\small}]
    (n1)edge [] node[left]{} (n2)
        edge [] node[left]{} (n3)
    (n2)edge [] node[left]{} (n4)
        edge [] node[left]{} (n5)
    (n3)edge [] node[left]{} (n6)
        edge [] node[left]{} (n7);
\end{tikzpicture}
}
}
\\
\qquad
\resizebox{.55\linewidth}{!}{%
\subfigure{
\begin{tikzpicture}[<-,shorten >=1pt,auto,
  thick,main node/.style={circle,draw,font=\sffamily\Large\bfseries}]
  [scale=.40,auto=right,every node/.style={circle}]
  \node (n7) at (6,1) {4};
  \node (n6) at (4,1) {2};
  \node (n5) at (3,1)  {3};
  \node (n4) at (1,1)  {1};
  \node (n3) at (5,2) {2};
  \node (n2) at (2,2)  {1};
  \node (n1) at (3.5,3)  {1};
  \path [every node/.style={font=\sffamily\small}]
    (n1)edge [blue, solid] node[left]{} (n2)
        edge [blue, solid] node[left]{} (n3)
    (n2)edge [red, dashed] node[left]{} (n4)
        edge [red, dashed] node[left]{} (n5)
    (n3)edge [red, dashed] node[left]{} (n6)
        edge [red, dashed] node[left]{} (n7);
\end{tikzpicture}
}
}
\resizebox{.38\linewidth}{!}{%
\subfigure{
\begin{tikzpicture}[<-,shorten >=1pt,auto,
  thick,main node/.style={circle,draw,font=\sffamily\Large\bfseries}]
  [scale=.70,auto=right,every node/.style={circle}]
  \node (n7) at (4,1) {4};
  \node (n5) at (1,1)  {3};
  \node (n3) at (3,1) {2};
  \node (n1) at (2,1)  {1};
        
  \path [every node/.style={font=\sffamily\small}]
    (n1)edge [blue, solid, loop above, looseness=12, in=135,out=30] node[]{} (n1)
        edge [blue, solid] node[]{} (n3)
        edge [red, dashed, loop above, looseness=10,in=105,out=60] node[]{} (n1)
        edge [red, dashed] node[]{} (n5)
    (n3)edge [red, dashed, loop above, looseness=10,in=105,out=60] node[]{} (n3)
        edge [red, dashed] node[]{} (n7);

\end{tikzpicture}
}
}
\end{figure}
\end{document}